During
a recent ecology field trip with a college class, the smell of insect
repellent masked the otherwise pervasive natural odors of swamp mud
and vegetation. The occasional slap of a student hitting their own arm
or face gave further evidence of the ongoing battle being waged against
blood-sucking mosquitoes and deerflies.

The scene
reminded me of an ethical dilemma faced by ecologists and environmentalists.
How does one justify getting rid of biting pests that are simply trying
to get a meal while at the same time taking a strong environmental stand
about preserving other forms of wildlife?

How can
ecologists make appeals to protect man-eating crocodiles, tigers and
sharks while holding a callous attitude toward a variety of insects?

Full-scale
attacks on certain lower life-forms are considered acceptable by most
people, including ecologists. A friend of mine who works with horses
has a special dislike for horseflies.

Most of
us take immediate action with intent to kill as soon as a horsefly lands
on us, but she strikes before the flies do. She has investigated ways
to deal with them around a barn where they are decidedly unwanted.

One technique
she uses is to suspend an inflated black garbage bag or balloon from
a 6-foot-high tripod. Above that she places a large funnel of clear
plastic with the large end down. The small end leads into a plastic
3-liter bottle.

Horseflies
and deerflies are attracted to the dark object, which presumably resembles
a horse or cow, and fly up the funnel and into the bottle. Flies try
to escape by flying upward, so all soon die in the jug.

The technique
can rid a stable of hundreds of flies in a few days. Although she is
an ecologist and environmentalist, she finds this an acceptable solution
to the problem of flies that bite her livestock.

What is
the distinction between animals we feel should be protected and those
that we kill on sight? One difference is that we seem to be in little
danger of losing any of the noxious insects. Their replacement capacities
seem limitless. No matter how many mosquitoes you swat in a salt marsh,
more will arrive to take their place on your arms and face.

Another
distinction is that biting insects and ticks attack us and our pets,
even in our own homes, without provocation. They find us and invade
our privacy. It would be a strange person indeed who would willingly
agree to be a meal for another animal.

Most people
consider these insects pests with few redeeming qualities to compensate
for their bad habits. This is of course a totally self-oriented attitude
on our part, but this is the way of the world, as run by humans.

Another
human attitude that we may be less conscious of is that we tend to protect
creatures more closely related to us or that have some feature we appreciate.
Mammals and birds are warm-blooded animals that, like humans, care for
their young. A furry or feathered animal, especially if the species
is waning in numbers, has our empathy. Likewise, humans appreciate color,
and so insects with bright colors or striking patterns are more likely
to be acceptable life-forms to us. Few people kill butterflies on purpose.

An additional
strike against many flies and mosquitoes is that they do more than get
a free meal from us. They can leave a lasting memory in the form of
parasites that enter the bloodstream.

Even today,
malaria is one of the leading causes of death worldwide. Lyme disease
from ticks and bubonic plague from fleas have not endeared those animals
to us.

Nonetheless,
I think a key factor for many of us is that we know we are not endangering
one of these species by swatting it, even before it bites us. That knowledge
certainly colors my attitude. I really would not want to be the person
responsible for the extinction of any species, even horseflies.